Portable tar spraying machine



March 21, 1939. w. E. HADLEY PORTABLE TAR SPRAYING MACHINE Filed Sept. 25, 1936 2 Sheets-Sheet l 1 ZZZ/6723?.- WzZZerE/E/ March 21, 1939. w, E HADLEY 2,151,100

I PORTABIIJE TAR SPRAYING MACHINE Filed Sept. '25, 1956 2 Sheets-Sheet 2 mun-H,

Patented Mar. 21, 1939 UNITED STATES PATENT OFFICE 3 Claims.

The invention relates to apparatus for coating ingot molds with tar or other coating material and although particularly applying to the art of producing ingots of steel, may be used with equalportable tar coating apparatus that can be operated from the cage of the crane by which it is carried and which will render it possible to control the thickness of the coating material applied 20 to the interior of the mold.

The practice of coating the mold walls with tar or other mold washes is almost as old as the casting of steels in molds itself. The general purpose is to obtain a cleaner, smoother surface on the ingot and ultimately a better product and to additionally prolong the life of the mold.

The function of tar or any other mold wash is to provide an insulator for the mold walls to insulate the same against contact with the hot steel. Liquid steel when poured into the molds has a temperature of about 2600 degrees Fahr;

while the temperature of the mold is about 140 degrees Fahr. When the hot steel comes in contact with the mold wall there is almost instan- 3 taneous rise in temperature of the mold wall surface from 140 degrees Fahr. to about 1500 degrees Fahr. and just as sudden a. drop in temperature of the steel adjacent the mold wall from 2800 degrees Fahr, to about 1500 degrees Fahr. While the sudden rise in temperature of the mold wall surface is responsible for fire cracking of the mold surface, which in turn makes the ingot surface rough, checked and imperfect, the sudden drop in the temperature of the steel adjacent the mold wall is the cause of undue contraction of the ingot skin which in some cases results in ingot cracks and in all cases produces internal strains in the ingot which are harmful in subsequent application. By applying a tar coating to the walls of the ingot mold a cushion and insulator is provided for tempering the abrupt temperature changes.

When too much tar is applied to the mold the benefits derived from it are offset by the fact that some of the surplus tar is entrapped between the Another object of the invention is to provide mold wall and the ingot and is responsible for blow holes in the ingot surface. Heretofore the tar coating has been applied by dipping the mold into a tank or reservoir of tar. This method has several disadvantages, first, the coating is unnecessarily applied to the outside walls of the mold as well as to the inside walls, making the tar usage almost twice as high as need be, second, the outside tar coating causes great inconvenience to the men working in the plant due to the tarry smoke distilled ofi the molds after the molten steel is poured into them, and third, the method can be controlled to a slight degree only th regard to the thickness of the wash on the inside walls of the mold with injurious results to the ingot as explained above. The present invention makes it possible to eliminate the tar coating on the outside entirely and further eliminates the smoke nuisance and permits positive control of the quantity of tar applied to the inside walls, thus eliminating the difllculties arising from too heavy a coating of tar.

With these and various other objects in view, the invention may consist of certain novel features of construction and operation, as will be more fully described and particularly pointed out in the specification, drawings and claims appended hereto. 1

In the drawings which illustrate an embodiment of the invention and wherein like reference characters are used to designate like parts Figure l is a vertical sectional view of tar coating apparatus constructed in accordance with the invention;

Figure 2 is an enlarged plan view of the spinner showing the vanes thereon;

Figure 3 is an elevational view of the structure shown in Figure 2;

Figure 4 is an enlarged plan view of the stationary cone;

Figure 5 is a vertical sectional view taken substantialy along line 55 of Figure 4;

Figure 6 is a horizontal sectional view taken substantially along line B6 of Figure 1; and

Figure '7 is a wiring diagram showing the electrical connections between the operating parts of the apparatus and the hoisting means of the crane from which the apparatus is suspended.

The operating motor and valve control means for the tar spraying apparatus is housed within a cylindrical carriage l0 having a base member II which is suspended by a chain or cable l2 through the hook It. The tar reservoir of the apparatus consists of a tubular member I5 suitably secured to the base H of the housing I0 by the threaded connection It and is provided with a plurality of openings I I located in the upper part thereof by which tar is admitted to the interior of the member to fill the same. The lower end thereof is closed by a base l8 suitably secured thereto by the screws l9 and located immediately above openings 20.

Located concentrically with respect to the tubular member I5 is a tube 2| which extends from the base member II to the base l8, the said tube protecting the drive shaft 22 from direct contact with the tar in the reservoir. The said drive shaft is suitably joined by connection 23 to the rotor shaft 24 of the electric motor 25 which is supported within the housing ID in elevated position by the uprights 26 secured at 21 to the motor base 28. Substantially frictionless rotation of the rotor of said motor is provided for by the ball bearing assembly 38 which in efiect supports the rotor upon the base 28.

The drive shaft extends through a bearing 3| in the base l8 and has fixed to its depending end so as to rotate therewith a cone-shaped spinner 32. As more particularly shown in Figures 2 and 3 arcuate vanes 33 are formed on the upper surface of the spinner which traverse the surface from the hub thereof to the circumference. The spinner is rotated at a high speed and the vanes mechanically promote the fine division of the tar blanket which is sprayed onto the interior surfaces of the mold. A stationary cone 34 is associated with the spinner, being located above the same in spaced relation with respect to the vanes 33. The collar 35 forms a small reservoir for the tar which eventually enters the space between the spinner and cone,

whereupon it is picked up by the vanes and ejected as a fine spray from the lower end of the parts.

The cone is supplied with tar from the tubular member l5 through the valve 36 and tube 31 which connects the valve and the cone. The portion of the valve projecting above the base I8 is provided with a plurality of openings 38 which may be closed by the rod 48 having vertical movement within the projecting portion of the valve. The upper end of the rod is pivotally connected at 4| to the yoke 42 which is hinged by shaft 43 supported for rotation in brackets 44 suitably secured to uprights 26. The yoke is provided with a single projecting member 45 which pivotally connects at 46 with the armature 41 of the solenoid 48 supported by the frame 49 from the uprights. Energization of the solenoid will rock the yoke 42 and thus raise the rod 40, opening the valve 36 to admit tar to the spinner. The openings 38 of said valve are -located in several horizontal planes and therefore the quantity of tar admitted through said openings can be regulated by the extent to which rod 40 is raised. This action of the rod is in turn controlled by nut 50 which accordingly regulates the thickness of the tar coating applied by the apparatus.

In operation the apparatus is suspended from a crane or the like by the chain or cable l2 and the tubular member I5 is first filled with hot tar by immersing the member into a reservoir of hot tar until the samefiows through the opening I1. The apparatus is then lowered to within a few inches of the bottom of the mold. The motor 25 is then started, rotating the spinner 32 at a high speed. Following this the hoist controller is operated and the apparatus begins to rise and simultaneously therewith solenoid 48 is energized, lifting rod 48 to the maximum extent permitted by nut 58. This supplies the spinner with tar which is ejected as a fine spray from the circumference thereof to coat the inside surfaces of the mold to the thickness desired, it being of course understood that the apparatus continues to rise so that the tar coating is substantially uniform.

Figure 7 shows a wiring diagram comprising the electrical connections between the apparatus and the hoist controller of the crane carrying the apparatus. Power is supplied from any suitable source by the conductors LI and L2 which electrically connect with a controller 5| for the spray motor, the contacts 52 being closed when said motor is started. The contacts 53 are located on the hoist controller and the same are closed only in hoist position of said controller. With the spray motor in operation, contacts 52 are closed and with the hoist controller in hoisting position contacts 53 will be closed, closing the circuit through the contactor 54 which upon energiization actuates switch 55. As soon as switch 55 is closed the solenoid 48 is energized, actuating valve 36 as above described. When the'apparatus reaches the top of the mold the spray motor is stopped by the operator. Therefore it will be clear from the foregoing that it is impossible for the crane operator to open the valve 38 to admit tar to the rotating spinner except when hoisting the spray apparatus.

The invention is not to be limited to or by details of construction of the particular embodiment thereof illustrated by the drawings, as various other forms of the device will of course be apparent to those skilled in the art without departing from the spirit of the invention or the scope of the claims.

What is claimed is:

1. Portable spraying apparatus adapted to be suspended by a crane or the like and to be hoisted and lowered by said crane comprising a reservoir for containing a quantity of coating material to be sprayed thereby, a spraying device located below the reservoir, a motor for rotating said spraying device, electromagnetic means for controlling the delivery of the coating material from the reservoir to the spraying device, and electrical connections between said electromagnetic means and the crane whereby said electromagnetic means can be energized only when said crane is hoisting the spraying apparatus.

2. Portable apparatus for coating the inside of ingot molds and the like, comprising a casing housing an electric motor, a tubular member depending from the casing and providing a reservoir for the coating material, a drive shaft connecting with the motor and extending through the reservoir, a spinner fixed to the depending end of the drive shaft and operating when rotated at high speed to eject the coating material in'the form of a fine spray, a valve located in the base of said reservoir for controlling the delivery of the coating material from the reservoir to the spinner, means extending through the reservoir having association with said valve for opening and closing the same, and an electromagnet located in the casing connecting with said means for actuating the same.-

3. Portable apparatus for coating the inside of ingot molds and the like, comprising a casing housing an electric motor, a tubular member depending from the casing providing a reservoir for the coating material, said member having openings in the upper part thereof through which the trolling the delivery of the coating material from the reservoir to the spinner, means extending through the reservoir having association with said valve for opening and closing the same, and an electromagnet located in the casing connecting 5 with said means for actuating the same.

WALTER E. HADLEY. 

